Which process allows animals to convert food into energy?

Cellular respiration is the process by which animals convert food into energy. It involves breaking down glucose and other organic molecules obtained from food in the presence of oxygen (aerobic respiration) to produce adenosine triphosphate (ATP), which serves as the energy currency for cells. During this metabolic process, animals utilize the energy stored in chemical bonds of the food, releasing carbon dioxide and water as byproducts.

In contrast, photosynthesis is a process exclusive to plants, algae, and some bacteria, where they convert light energy into chemical energy in the form of glucose. Transpiration refers to the movement of water within plants and its evaporation from aerial parts, primarily leaves, which is unrelated to energy conversion in animals. Digestion is the physical and chemical process that breaks down food into smaller molecules that can be absorbed, but it does not itself directly convert food into energy; that conversion occurs in the subsequent cellular respiration process.